Anyone for that question?




2013/3/28 Pierre Antoine DuBoDeNa <padbdn@gmail.com>

> Hello,
>
> I want to use pearson's correlation as distance between observations and
> then use any centroid based linkage distance (ex. Ward's distance)
>
> When linkage distances are formed as the Lance-Williams recursive
> formulation, they just require the initial distance between observations.
> See here: http://en.wikipedia.org/wiki/Ward%27s_method
>
> It is said that you have to use euclidean distance between the initial
> observations. However i have found this:
>
> http://research.stowers-institute.org/efg/R/Visualization/cor-cluster/
>
> where they use pearson's correlation for hierarchical clustering.
>
> Any idea if anything is violated in case pearson's correlation is used
> with Ward's linkage function?
>
> the dissimilarity of pearson's correlation can be defined as d =
> sqrt(1-pearsonsimilarity^2). can that be considered as norm1 distance? and
> thus norm2 if we square it? so that the wikipedia's statement "To apply a
> recursive algorithm under this objective function, the initial distance
> between individual objects must be (proportional to) squared Euclidean
> distance." is valid?
>
> Best,
> Pierre
>

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